Cholesteric liquid crystal light modulators

Abstract

This invention relates to a method of fabrication of liquid crystal light modulating devises having electrically tunable spectral wavelength and more particularly, to a cholesteric liquid crystal display with electrically switchable colors. The cholesteric light modulators may be fabricated by applying a plurality of layers to maximize the light modulation. It also features a polymer composite or polymer-network stabilized cholesteric liquid crystal with electrically switchable Bragg reflected wavelength within a predetermined range of spectral wavelength.

Description

[0001]The present application claims priority from and the benefit of the filing date of Provisional Patent Application Nos. 60 / 836,093 and 60 / 836,094, both filed Aug. 7, 2006.BACKGROUND[0002]A cholesteric liquid crystal will adopt a helical structure with the director rotating around an axis perpendicular to the substrate surfaces in an electro-optical cell with homogeneous alignment. Because of the self-assembled helical structure of cholesteric liquid crystal, in the planar texture where cholesteric helix is aligned vertically, the incident light is decomposed into its right and left circular components with one component reflected and the other transmitted. The unique ability of a cholesteric liquid crystal to reflect light comes from their helical superstructure. The central reflected wavelength (λo) in a direction normal to the surface can be described as λ0= n·p= n·(C·HTP)−1, where p is the helical pitch, in which the director rotates 360 degree, n is the average refractive i...

AI Technical Summary

Benefits of technology

[0010]This present embodiments provide a method of fabricating liquid crystal light modulating devices comprising a cholesteric liquid crystal. In general, the present invention provides a method for fabricating light modulating devices, comprising a pair of substrates with transparent conductive electrodes, providing alignment layers for planar alignment, and depositing a cholesteric liquid crystal

Problems solved by technology

While the feasibility has been demonstrated, there is a loss in reflective brightness.

The bottleneck for the full color cholesteric displays to be realized commercially resides in the production yield and cost.

For example, to display a full color image it requires three color cholesteric films and electronic drivers which increase the cost of the display.

Furthermore, the shift register of pixels from separate panels causes parallax problem.

As a result, the yield in producing full color dis

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